Molecular Imprinting Sensor Of Sulfa Drug

Molecular imprinting technology (MIT) is a new technique forpreparing specialized recognition media. The basic principle is that theimprinting template molecules, functional monomer and cross-linkingagent were dissolved in a solvent, and were having complementaryfunctional polymerization. After extracting the template molecules fromthe polymer, the polymer leaves cavities inside the polymers which arecomplementary in terms of size, shape, and functional groups orientationto those of the template molecules. Thus, it is shown specific selectivityand adsorption capacity of the template molecules. The technique hasbeen applied in many fields widely. With the characteristic ofpredetermination, recognition and practicability, MIPs are used in manyfields, such as chiral separation of enantiomer and isomer, clinical druganalysis, enzyme-minic catalyzed reaction, solid phrase extraction,chemical bionics sensor and film separation. In particular, molecularlyimprinted membrane has both advantages of the membrane and molecularimprinted polymer, so that molecularly imprinted membrane is becomingthe hot topic of research in the field of electrochemical sensors. But themolecularly imprinted membrane is usually thick and highly cross-linked,incomplete template removal, reproducibility, bad reversibility and so on,which limited application of molecularly imprinted membrane inelectrochemical sensors. So studies are encouraged to find newmonomers and new methods to extend the molecularly imprintedmembrane-electrochemical sensor. This paper gives a brief overview of the development of themolecularly imprinted technology (MIT) and the application of themolecularly imprinted membrane in the electrochemical sensors. Andfour novel molecularly imprinted membrane electrochemical sensors areprepared form different monomers and the characters of the sensors.Furthermore, the MIPs are investigated the ability of drug analysis by theelectro-chemical methods.1.A molecularly imprinted polymer(MIP）film for the determinationof sulfamethoxazole was fabricated onto a glassy carbon electrode usingethylene glycol maleic rosinate acrylate as the cross linking agent,methacrylic acid as functional monomer by the free radicalpolymerization method. The performance of the imprinted film wasinvestigated by cyclic voltammetry (CV), differential pulse votammetry(DPV) and electrochemical impedance spectroscopy (EIS). Under theoptimum experimental conditions, the DPV peak current showed a lineardependence on the sulfamethoxazole concentration in the ranges of1.0×10-6～1.6×10-4mol/Lmol/L and4.0×10-4～1.4×10-2mol/L mol/L ofsulfamethoxazole （each correlation coefficient of0.9959and0.9970,respectively）with the detection limit (S/N=3) of3.0×10-7mmol/L. Thiselectrode displayed selective and reproducibility binding s ites forsulfamethoxazle. The prepared sensor was successfully applied to thedetermination of sulfamethoxazle in Paediatric CompoundSulfamethoxazole Tablet samples with recovery ranging from95%to104%.2. Based on the combination of self-assembled andelectropolymerized methods, an electrochemical molecularly imprintedsensor for specific sulfamethoxazole (SMZ) recognition was preparedusing sulfamethoxazole as a template, methacrylic acid as a functionalmonomer, modified maleic rosin acrylate glycol ester as cross-linker. Theperformance of the electrochemical sensor was characterized by cyclicvoltammetry (CV), differential pulse voltammetry (DPV), andamperometric i-t curve. The experimental results show that the sensor hasgood selectivity and high sensitivity to the target molecular. The linearrange is from5.0×10-6～2.4×10-3mol/L with the detection limit of 1.67×10-7mol/L（S/N=3）. The response time of stable current was foundto be less than two seconds. The sensor has been successfully employedto the determination of sulfamethoxzole in compound sulfamethoxazoleTablets.3. With containing the skeleton maleic rosin ethylene glycol acrylateresin as a crosslinking agent, sulfadiazine as imprinted molecule,methacrylic acid as functional monomer, by way of free radicalpolymerization in the glassy carbon electrode surface stable sulfadiazinemolecularly imprinted sensor has been developed. By differential pulsevoltammetry, cyclic voltammetry and AC impedance method to explorethe sensor response characteristic of sulfadiazine. Under the optimizedexperimental conditions, the response of the electrochemical sensorcurrent and sulfadiazine concentration had good linear relationship withinrange2.0×10-7mol/L～4.3×10-4mol/L, detection limit is2.4×10-7mol/L. Thesensor has good reproducibility, selectivity and stability, and used fordetermination of sulfonamide sulfadiazine content, the average recoverywas97%~101%.4. Using molecular imprinting technology, methacrylic acid asfunctional monomer, sulfadiazine as template molecule, maleic rosinethylene glycol acrylate resin as the crosslinking agent, on the surface ofglassy carbon electrode by electrochemical polymerization synthesis ofsulfadiazine molecularly imprinted sensor. By cyclic voltammetry (CV)and ac impedance spectroscopy (EIS) study the electrochemical behaviorof the molecularly imprinted sensor. Results show that the optimalexperimental conditions, the1.0×10-7～9.0×10-4mol/L range,sulfadiazine concentration and the current response of the sensor valuefor good linear relationship (R2=0.993), the detection limit of3.7×10-8mol/L, reproducibility and stability of the developed sensor performanceis good, has a good choice to performance, applied to the determinationof content of sulfadiazine drugs, have achieved satisfactory results.